Hi Tommaso,
I see your point. You would like that the axis labels change according to
the function, isn't it ? This not how this feature is working. In fact is
works exactly the same as the Logy and Logx options: When you "set on" one
of these options, the axis tick marks are positioned according to a log
scale but the axis labels keep their "linear values". So when you use a
function to create an axis, the tick marks will be positioned according to
this function but the axis labels will keep their "linear values".
Therefore adding or subtracting a constant has no visible effect, because
it just performs a translation of a linear scale so it remains linear. I
have attached a little macro creating a few axis showing this.
Cheers, Olivier
On Wed, 10 Mar 2004, Tommaso Chiarusi wrote:
> Ok, the algorithm is simply
> fu = 90 -x[0];
>
> But the substance of the problem does not change: with this function
> the range is not modified as I wanted...
>
>
> ok...
> On Wed, 10 Mar 2004, Olivier Couet wrote:
>
> >
> >
> >
> > Hi Tommaso,
> >
> > are you sure that the real algorithm is:
> >
> > if(x[0]<=90) fu = 90 - x[0];
> > else fu = 90-x[0];
> >
> > ??
> >
> > because seems to me these two lines are the same as:
> >
> > fu = 90-x[0];
> >
> > Cheers, Olivier
> >
> >
> > On Wed, 10 Mar 2004, Tommaso Chiarusi wrote:
> >
> > > Hi Olivier,
> > > you were right, I made a mistake, in fact the real algorithm is
> > >
> > > if(x[0]<=90) fu = 90 - x[0];
> > > else fu = 90-x[0];
> > >
> > > and not
> > > else fu = x[0]-270;
> > >
> > > Well yesterday I fused...:)
> > >
> > >
> > > buy the way the devicing fact is that, neither with the
> > > correct algorithm, the labels on to the plot are not modified
> > > accordingly!!!
> > > In fact I get simply
> > > 180 160 140 120 100 80 60 40 20 0
> > >
> > > Moreover, if in the function you set:
> > > fu = x[0]*2;
> > >
> > > just for trying, you get no effect on the range.
> > >
> > > may be I didn't well understand how TGaxis works with a function.
> > >
> > > any suggestion?
> > > Thank you.
> > > Tommaso
> > >
> > > On Wed, 10 Mar 2004, Olivier Couet wrote:
> > >
> > > >
> > > > Hi Tommaso,
> > > >
> > > > I looked closer at your examples. I agree with you that the first one
> > > > transform the following labels:
> > > >
> > > > -80 -60 -40 -20 0 20 40 60 80
> > > >
> > > > into:
> > > >
> > > > 80 60 40 20 0 -20 -40 -60 -80
> > > >
> > > > But, seems to me the 2nd example transform:
> > > >
> > > > 0 20 40 60 80 100 120 140 160 180
> > > >
> > > > into:
> > > >
> > > > 90 70 50 30 10 -170 -150 -130 -110 -90
> > > >
> > > > Which, I guess, is not what you want. I think you did a mistake in your
> > > > 2nd example.
> > > >
> > > > Cheers, Olivier
> > > >
> > > >
> > > > On Tue, 9 Mar 2004, Tommaso Chiarusi wrote:
> > > >
> > > > >
> > > > > Hello everybody:
> > > > >
> > > > > OS Linux RH 9
> > > > > ROOT 3.10/02 16 December 2003
> > > > >
> > > > > well, I need to reset the labels onto an histogram.
> > > > > It has the x axis which ranges from 0 to +180
> > > > > I like it to span from +90 to -90 (yes from positive to negative
> > > > > like 90 80 70..10 0 -10 ... -80 -90).
> > > > >
> > > > > So decided to
> > > > > TGaxis method together with a function
> > > > >
> > > > >
> > > > > So I've written the function:
> > > > >
> > > > > double funz(double *x,double *par)
> > > > > {
> > > > > double fu=0;
> > > > > fu = -x[0];
> > > > > return fu;
> > > > > }
> > > > >
> > > > > and in the body of the macro,
> > > > >
> > > > > TF1 *f = new TF1("f",funz,-90,90,0);
> > > > > TGaxis *tga = new TGaxis(0,0,180,0,"f",510);
> > > > > tga->Draw();
> > > > >
> > > > > and it works!
> > > > >
> > > > > note that the spanning of the new scale is independent from the original
> > > > > range.
> > > > > -----
> > > > > THE QUESTION:
> > > > >
> > > > > Why the following doesn't give the same result?
> > > > >
> > > > > I redefine the function,
> > > > >
> > > > > double funz(double *x,double *par)
> > > > > {
> > > > > double fu=0;
> > > > > if(x[0]<=90) fu = 90 -x[0];
> > > > > if(x[0]>90) fu = x[0]-270;
> > > > >
> > > > > return fu;
> > > > > }
> > > > >
> > > > > and in the body of the macro,
> > > > >
> > > > > TF1 *f = new TF1("f",funz,0,180,0);
> > > > > TGaxis *tga = new TGaxis(0,0,180,0,"f",510);
> > > > > tga->Draw();
> > > > >
> > > > > note the different range for f
> > > > >
> > > > > Best regards, Tommaso
> > > > >
> > > > > P.S.
> > > > > is this mailing list hard-contamined by spam?
> > > > > is it true that it will be removed by the CERN mailing list?
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
--
Org: CERN - European Laboratory for Particle Physics.
Mail: 1211 Geneve 23 - Switzerland Mailbox: J25910
E-Mail: Olivier.Couet@cern.ch Phone: +41 22 7676522
WWW: http://cern.ch/Olivier.Couet/ Fax: +41 22 7677155
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